Large-Eddy Simulations of Turbulent Flows around Buildings Using the Atmospheric Boundary Layer Environment–Lattice Boltzmann Model (ABLE-LBM)

Abstract

ABSTRACTA three-dimensional, prognostic Atmospheric Boundary Layer Environment–Lattice Boltzmann Model (ABLE-LBM) using the multiple-relaxation-time lattice Boltzmann method was developed for large-eddy simulation of urban boundary layer atmospheric flows. In this article we describe the details of the ABLE-LBM for urban flow, its implementation of complex boundaries, and the subgrid turbulence parameterizations. As a first validation of this newly developed model, the simulation results were evaluated with two wind-tunnel datasets that were collected using particle image velocimetry and Irwin probes, respectively. The ABLE-LBM simulations use the same building layout and Reynolds numbers used in the laboratory wind tunnels. The ABLE-LBM simulations compare favorably to both laboratory studies in terms of the mean wind fields. The turbulent fluxes simulated by the model in the observational planes also agreed reasonably well with the laboratory results. The model produced urban canyon flows and vortices on the lee side and over the building tops that are similar to those of the laboratory studies in strength and location. This validation study using laboratory data indicates that our new ABLE-LBM is a viable approach for modeling atmospheric turbulent flows in urban environments. A numerical implementation using a graphics processing unit shows that real-time simulations are achieved for these two validation cases.